1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CAN bus driver for the Freescale MPC5xxx embedded CPU. 4 * 5 * Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>, 6 * Varma Electronics Oy 7 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com> 8 * Copyright (C) 2009 Wolfram Sang, Pengutronix <kernel@pengutronix.de> 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/interrupt.h> 14 #include <linux/platform_device.h> 15 #include <linux/property.h> 16 #include <linux/netdevice.h> 17 #include <linux/can/dev.h> 18 #include <linux/of.h> 19 #include <linux/of_address.h> 20 #include <linux/of_irq.h> 21 #include <linux/of_platform.h> 22 #include <sysdev/fsl_soc.h> 23 #include <linux/clk.h> 24 #include <linux/io.h> 25 #include <asm/mpc52xx.h> 26 27 #include "mscan.h" 28 29 #define DRV_NAME "mpc5xxx_can" 30 31 struct mpc5xxx_can_data { 32 unsigned int type; 33 u32 (*get_clock)(struct platform_device *ofdev, const char *clock_name, 34 int *mscan_clksrc); 35 void (*put_clock)(struct platform_device *ofdev); 36 }; 37 38 #ifdef CONFIG_PPC_MPC52xx 39 static const struct of_device_id mpc52xx_cdm_ids[] = { 40 { .compatible = "fsl,mpc5200-cdm", }, 41 {} 42 }; 43 44 static u32 mpc52xx_can_get_clock(struct platform_device *ofdev, 45 const char *clock_name, int *mscan_clksrc) 46 { 47 unsigned int pvr; 48 struct mpc52xx_cdm __iomem *cdm; 49 struct device_node *np_cdm; 50 unsigned int freq; 51 u32 val; 52 53 pvr = mfspr(SPRN_PVR); 54 55 /* 56 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock 57 * (IP_CLK) can be selected as MSCAN clock source. According to 58 * the MPC5200 user's manual, the oscillator clock is the better 59 * choice as it has less jitter. For this reason, it is selected 60 * by default. Unfortunately, it can not be selected for the old 61 * MPC5200 Rev. A chips due to a hardware bug (check errata). 62 */ 63 if (clock_name && strcmp(clock_name, "ip") == 0) 64 *mscan_clksrc = MSCAN_CLKSRC_BUS; 65 else 66 *mscan_clksrc = MSCAN_CLKSRC_XTAL; 67 68 freq = mpc5xxx_get_bus_frequency(&ofdev->dev); 69 if (!freq) 70 return 0; 71 72 if (*mscan_clksrc == MSCAN_CLKSRC_BUS || pvr == 0x80822011) 73 return freq; 74 75 /* Determine SYS_XTAL_IN frequency from the clock domain settings */ 76 np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids); 77 if (!np_cdm) { 78 dev_err(&ofdev->dev, "can't get clock node!\n"); 79 return 0; 80 } 81 cdm = of_iomap(np_cdm, 0); 82 if (!cdm) { 83 of_node_put(np_cdm); 84 dev_err(&ofdev->dev, "can't map clock node!\n"); 85 return 0; 86 } 87 88 if (in_8(&cdm->ipb_clk_sel) & 0x1) 89 freq *= 2; 90 val = in_be32(&cdm->rstcfg); 91 92 freq *= (val & (1 << 5)) ? 8 : 4; 93 freq /= (val & (1 << 6)) ? 12 : 16; 94 95 of_node_put(np_cdm); 96 iounmap(cdm); 97 98 return freq; 99 } 100 #else /* !CONFIG_PPC_MPC52xx */ 101 static u32 mpc52xx_can_get_clock(struct platform_device *ofdev, 102 const char *clock_name, int *mscan_clksrc) 103 { 104 return 0; 105 } 106 #endif /* CONFIG_PPC_MPC52xx */ 107 108 #ifdef CONFIG_PPC_MPC512x 109 static u32 mpc512x_can_get_clock(struct platform_device *ofdev, 110 const char *clock_source, int *mscan_clksrc) 111 { 112 struct device_node *np; 113 u32 clockdiv; 114 enum { 115 CLK_FROM_AUTO, 116 CLK_FROM_IPS, 117 CLK_FROM_SYS, 118 CLK_FROM_REF, 119 } clk_from; 120 struct clk *clk_in, *clk_can; 121 unsigned long freq_calc; 122 struct mscan_priv *priv; 123 struct clk *clk_ipg; 124 125 /* the caller passed in the clock source spec that was read from 126 * the device tree, get the optional clock divider as well 127 */ 128 np = ofdev->dev.of_node; 129 clockdiv = 1; 130 of_property_read_u32(np, "fsl,mscan-clock-divider", &clockdiv); 131 dev_dbg(&ofdev->dev, "device tree specs: clk src[%s] div[%d]\n", 132 clock_source ? clock_source : "<NULL>", clockdiv); 133 134 /* when clock-source is 'ip', the CANCTL1[CLKSRC] bit needs to 135 * get set, and the 'ips' clock is the input to the MSCAN 136 * component 137 * 138 * for clock-source values of 'ref' or 'sys' the CANCTL1[CLKSRC] 139 * bit needs to get cleared, an optional clock-divider may have 140 * been specified (the default value is 1), the appropriate 141 * MSCAN related MCLK is the input to the MSCAN component 142 * 143 * in the absence of a clock-source spec, first an optimal clock 144 * gets determined based on the 'sys' clock, if that fails the 145 * 'ref' clock is used 146 */ 147 clk_from = CLK_FROM_AUTO; 148 if (clock_source) { 149 /* interpret the device tree's spec for the clock source */ 150 if (!strcmp(clock_source, "ip")) 151 clk_from = CLK_FROM_IPS; 152 else if (!strcmp(clock_source, "sys")) 153 clk_from = CLK_FROM_SYS; 154 else if (!strcmp(clock_source, "ref")) 155 clk_from = CLK_FROM_REF; 156 else 157 goto err_invalid; 158 dev_dbg(&ofdev->dev, "got a clk source spec[%d]\n", clk_from); 159 } 160 if (clk_from == CLK_FROM_AUTO) { 161 /* no spec so far, try the 'sys' clock; round to the 162 * next MHz and see if we can get a multiple of 16MHz 163 */ 164 dev_dbg(&ofdev->dev, "no clk source spec, trying SYS\n"); 165 clk_in = devm_clk_get(&ofdev->dev, "sys"); 166 if (IS_ERR(clk_in)) 167 goto err_notavail; 168 freq_calc = clk_get_rate(clk_in); 169 freq_calc += 499999; 170 freq_calc /= 1000000; 171 freq_calc *= 1000000; 172 if ((freq_calc % 16000000) == 0) { 173 clk_from = CLK_FROM_SYS; 174 clockdiv = freq_calc / 16000000; 175 dev_dbg(&ofdev->dev, 176 "clk fit, sys[%lu] div[%d] freq[%lu]\n", 177 freq_calc, clockdiv, freq_calc / clockdiv); 178 } 179 } 180 if (clk_from == CLK_FROM_AUTO) { 181 /* no spec so far, use the 'ref' clock */ 182 dev_dbg(&ofdev->dev, "no clk source spec, trying REF\n"); 183 clk_in = devm_clk_get(&ofdev->dev, "ref"); 184 if (IS_ERR(clk_in)) 185 goto err_notavail; 186 clk_from = CLK_FROM_REF; 187 freq_calc = clk_get_rate(clk_in); 188 dev_dbg(&ofdev->dev, 189 "clk fit, ref[%lu] (no div) freq[%lu]\n", 190 freq_calc, freq_calc); 191 } 192 193 /* select IPS or MCLK as the MSCAN input (returned to the caller), 194 * setup the MCLK mux source and rate if applicable, apply the 195 * optionally specified or derived above divider, and determine 196 * the actual resulting clock rate to return to the caller 197 */ 198 switch (clk_from) { 199 case CLK_FROM_IPS: 200 clk_can = devm_clk_get(&ofdev->dev, "ips"); 201 if (IS_ERR(clk_can)) 202 goto err_notavail; 203 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 204 priv->clk_can = clk_can; 205 freq_calc = clk_get_rate(clk_can); 206 *mscan_clksrc = MSCAN_CLKSRC_IPS; 207 dev_dbg(&ofdev->dev, "clk from IPS, clksrc[%d] freq[%lu]\n", 208 *mscan_clksrc, freq_calc); 209 break; 210 case CLK_FROM_SYS: 211 case CLK_FROM_REF: 212 clk_can = devm_clk_get(&ofdev->dev, "mclk"); 213 if (IS_ERR(clk_can)) 214 goto err_notavail; 215 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 216 priv->clk_can = clk_can; 217 if (clk_from == CLK_FROM_SYS) 218 clk_in = devm_clk_get(&ofdev->dev, "sys"); 219 if (clk_from == CLK_FROM_REF) 220 clk_in = devm_clk_get(&ofdev->dev, "ref"); 221 if (IS_ERR(clk_in)) 222 goto err_notavail; 223 clk_set_parent(clk_can, clk_in); 224 freq_calc = clk_get_rate(clk_in); 225 freq_calc /= clockdiv; 226 clk_set_rate(clk_can, freq_calc); 227 freq_calc = clk_get_rate(clk_can); 228 *mscan_clksrc = MSCAN_CLKSRC_BUS; 229 dev_dbg(&ofdev->dev, "clk from MCLK, clksrc[%d] freq[%lu]\n", 230 *mscan_clksrc, freq_calc); 231 break; 232 default: 233 goto err_invalid; 234 } 235 236 /* the above clk_can item is used for the bitrate, access to 237 * the peripheral's register set needs the clk_ipg item 238 */ 239 clk_ipg = devm_clk_get(&ofdev->dev, "ipg"); 240 if (IS_ERR(clk_ipg)) 241 goto err_notavail_ipg; 242 if (clk_prepare_enable(clk_ipg)) 243 goto err_notavail_ipg; 244 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 245 priv->clk_ipg = clk_ipg; 246 247 /* return the determined clock source rate */ 248 return freq_calc; 249 250 err_invalid: 251 dev_err(&ofdev->dev, "invalid clock source specification\n"); 252 /* clock source rate could not get determined */ 253 return 0; 254 255 err_notavail: 256 dev_err(&ofdev->dev, "cannot acquire or setup bitrate clock source\n"); 257 /* clock source rate could not get determined */ 258 return 0; 259 260 err_notavail_ipg: 261 dev_err(&ofdev->dev, "cannot acquire or setup register clock\n"); 262 /* clock source rate could not get determined */ 263 return 0; 264 } 265 266 static void mpc512x_can_put_clock(struct platform_device *ofdev) 267 { 268 struct mscan_priv *priv; 269 270 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 271 if (priv->clk_ipg) 272 clk_disable_unprepare(priv->clk_ipg); 273 } 274 #else /* !CONFIG_PPC_MPC512x */ 275 static u32 mpc512x_can_get_clock(struct platform_device *ofdev, 276 const char *clock_name, int *mscan_clksrc) 277 { 278 return 0; 279 } 280 #define mpc512x_can_put_clock NULL 281 #endif /* CONFIG_PPC_MPC512x */ 282 283 static const struct of_device_id mpc5xxx_can_table[]; 284 static int mpc5xxx_can_probe(struct platform_device *ofdev) 285 { 286 const struct mpc5xxx_can_data *data; 287 struct device_node *np = ofdev->dev.of_node; 288 struct net_device *dev; 289 struct mscan_priv *priv; 290 void __iomem *base; 291 const char *clock_name = NULL; 292 int irq, mscan_clksrc = 0; 293 int err = -ENOMEM; 294 295 data = device_get_match_data(&ofdev->dev); 296 if (!data) 297 return -EINVAL; 298 299 base = of_iomap(np, 0); 300 if (!base) 301 return dev_err_probe(&ofdev->dev, err, "couldn't ioremap\n"); 302 303 irq = irq_of_parse_and_map(np, 0); 304 if (!irq) { 305 dev_err(&ofdev->dev, "no irq found\n"); 306 err = -ENODEV; 307 goto exit_unmap_mem; 308 } 309 310 dev = alloc_mscandev(); 311 if (!dev) 312 goto exit_dispose_irq; 313 platform_set_drvdata(ofdev, dev); 314 SET_NETDEV_DEV(dev, &ofdev->dev); 315 316 priv = netdev_priv(dev); 317 priv->reg_base = base; 318 dev->irq = irq; 319 320 clock_name = of_get_property(np, "fsl,mscan-clock-source", NULL); 321 322 priv->type = data->type; 323 priv->can.clock.freq = data->get_clock(ofdev, clock_name, 324 &mscan_clksrc); 325 if (!priv->can.clock.freq) { 326 dev_err(&ofdev->dev, "couldn't get MSCAN clock properties\n"); 327 goto exit_put_clock; 328 } 329 330 err = register_mscandev(dev, mscan_clksrc); 331 if (err) { 332 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n", 333 DRV_NAME, err); 334 goto exit_put_clock; 335 } 336 337 dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n", 338 priv->reg_base, dev->irq, priv->can.clock.freq); 339 340 return 0; 341 342 exit_put_clock: 343 if (data->put_clock) 344 data->put_clock(ofdev); 345 free_candev(dev); 346 exit_dispose_irq: 347 irq_dispose_mapping(irq); 348 exit_unmap_mem: 349 iounmap(base); 350 351 return err; 352 } 353 354 static void mpc5xxx_can_remove(struct platform_device *ofdev) 355 { 356 const struct mpc5xxx_can_data *data; 357 struct net_device *dev = platform_get_drvdata(ofdev); 358 struct mscan_priv *priv = netdev_priv(dev); 359 360 data = device_get_match_data(&ofdev->dev); 361 362 unregister_mscandev(dev); 363 if (data && data->put_clock) 364 data->put_clock(ofdev); 365 iounmap(priv->reg_base); 366 irq_dispose_mapping(dev->irq); 367 free_candev(dev); 368 } 369 370 #ifdef CONFIG_PM 371 static struct mscan_regs saved_regs; 372 static int mpc5xxx_can_suspend(struct platform_device *ofdev, pm_message_t state) 373 { 374 struct net_device *dev = platform_get_drvdata(ofdev); 375 struct mscan_priv *priv = netdev_priv(dev); 376 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base; 377 378 _memcpy_fromio(&saved_regs, regs, sizeof(*regs)); 379 380 return 0; 381 } 382 383 static int mpc5xxx_can_resume(struct platform_device *ofdev) 384 { 385 struct net_device *dev = platform_get_drvdata(ofdev); 386 struct mscan_priv *priv = netdev_priv(dev); 387 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base; 388 389 regs->canctl0 |= MSCAN_INITRQ; 390 while (!(regs->canctl1 & MSCAN_INITAK)) 391 udelay(10); 392 393 regs->canctl1 = saved_regs.canctl1; 394 regs->canbtr0 = saved_regs.canbtr0; 395 regs->canbtr1 = saved_regs.canbtr1; 396 regs->canidac = saved_regs.canidac; 397 398 /* restore masks, buffers etc. */ 399 _memcpy_toio(®s->canidar1_0, (void *)&saved_regs.canidar1_0, 400 sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0)); 401 402 regs->canctl0 &= ~MSCAN_INITRQ; 403 regs->cantbsel = saved_regs.cantbsel; 404 regs->canrier = saved_regs.canrier; 405 regs->cantier = saved_regs.cantier; 406 regs->canctl0 = saved_regs.canctl0; 407 408 return 0; 409 } 410 #endif 411 412 static const struct mpc5xxx_can_data mpc5200_can_data = { 413 .type = MSCAN_TYPE_MPC5200, 414 .get_clock = mpc52xx_can_get_clock, 415 /* .put_clock not applicable */ 416 }; 417 418 static const struct mpc5xxx_can_data mpc5121_can_data = { 419 .type = MSCAN_TYPE_MPC5121, 420 .get_clock = mpc512x_can_get_clock, 421 .put_clock = mpc512x_can_put_clock, 422 }; 423 424 static const struct of_device_id mpc5xxx_can_table[] = { 425 { .compatible = "fsl,mpc5200-mscan", .data = &mpc5200_can_data, }, 426 /* Note that only MPC5121 Rev. 2 (and later) is supported */ 427 { .compatible = "fsl,mpc5121-mscan", .data = &mpc5121_can_data, }, 428 {}, 429 }; 430 MODULE_DEVICE_TABLE(of, mpc5xxx_can_table); 431 432 static struct platform_driver mpc5xxx_can_driver = { 433 .driver = { 434 .name = "mpc5xxx_can", 435 .of_match_table = mpc5xxx_can_table, 436 }, 437 .probe = mpc5xxx_can_probe, 438 .remove = mpc5xxx_can_remove, 439 #ifdef CONFIG_PM 440 .suspend = mpc5xxx_can_suspend, 441 .resume = mpc5xxx_can_resume, 442 #endif 443 }; 444 445 module_platform_driver(mpc5xxx_can_driver); 446 447 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 448 MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver"); 449 MODULE_LICENSE("GPL v2"); 450